Current legislation regulates the obligations and responsibilities of persons who perform design, manufacture and use of equipment and installations in potentially explosive atmospheres with regard to compliance with explosion prevention requirements. There are two European Directives, so-called ATEx Directives, which regulate the placing on the European market of products intended for use in potentially explosive atmospheres and their safe use: Directive 2014/34/EU and Directive 1999/92/EC. The paper presents some aspects regarding the border situations where the two directives apply, in the case of assemblies of equipment to be assessed by a manufacturer in accordance with the Directive 2014/34/EU for putting on the market and the installations that are equipment assembled by the user under his responsibility and have to be assessed by users toward with the Directive 1999/92/EC requirements.

The explosion danger in all industries where explosive atmospheres generated by the mixture of combustible dusts or flammable gases with air may form, must be treated as a major hazard, as the explosions that may occur can seriously affect both health and safety people, as well as the environment. It is therefore necessary to assess the explosion risk and to establish appropriate measures to reduce it to acceptable levels in accordance with the requirements of the European Directives. An essential element in the assessment of the explosion risk for electrical and non-electrical equipment intended for use in potentially explosive atmospheres is the way in which an appropriate normal degree of protection is provided through the equipment housing (protection against touching of dangerous parts inside the equipment housing and protection against the ingress of dust and water inside it). The aim of the paper is to highlight compliance with the requirements of the ATEX Directive, given that this protection is a basic requirement for explosion protection and to present the important elements to be considered for the assessment of the normal degree of protection and the development of harmonized test methods with the requirements of European standards.

In industrial plants many types of combustible dusts are generated, processed, handled and stored. When ignited, they can burn rapidly and with a considerable explosion force, when mixed with air in proper proportions. This is the reason why adequate precautions have to be adopted, to ensure all equipment is appropriately protected so that the ignition likelihood of the explosive atmosphere is diminished. Explosion preventing and protection precautions aim to stop explosion occurrence, by eliminating or avoiding the conditions leading to explosions. The paper presents methods of determining dust explosion characteristics and combustion as well as their importance for a proper development and selection of prevention and protection measures. Once known, the protection/prevention measures can be correlated with the safety characteristics. For explosion protection and prevention a series of minimum mandatory requirements have to be fulfilled, for a safe handling and processing of solid materials having fine particle dimensions, among which some are mentioned: knowing the characteristics influencing safety, control and monitoring dust releases in technological processes, installations design for migrating and accumulation of dusts, respectively implementing a rigorous cleaning program at workplaces.

Carcasses of electrical or non-electrical equipment operating in potentially explosive atmospheres must provide a certain degree of protection against access to hazardous parts, penetration of solid bodies and/or water penetration, which must be tested according to the specifications of the Ex protection types. Normal protection classes are indicated by the international IP code followed by two characteristic digits referring to the protection against penetration of solid foreign bodies and water protection, followed by optional letters if required by the beneficiary according to the imposed conditions of use. Within the ENExEMEIP laboratory, have been developed laboratory tests to verify the first characteristic figure of the standard degree of protection according to the standardized European method. In the paper is presented the test stand of the large gauge equipment, a stand made with state-of-the-art equipment that provides the necessary performance for the accreditation of the test according to the standardized requirements. Checking dustproof protection to equipment used in areas where explosive atmospheres generated by combustion dust may occur is particularly important for assessing compliance with the requirements of the ATEX Directive [5], as this protection is a basic requirement for explosion protection.

Static electricity represents one of the potential ignition sources for the explosive atmospheres. The test methods for materials, in general, and especially the test methods for textile fabrics for assessment of the protective performances in static electricity, have known a permanent evolution alongside newly developed electrostatically dissipative materials. Within the National Institute of Research and Development for Safety in Mines and Explosion Protection (INCD-INSEMEX) new testing stands had been developed and new testing methods had been implemented for assessment of the charge dissipative capacity, in accordance with the European standards requirements. By modernizing the laboratory testing/research-development capacity, the physical tools for testing of materials are assured, having in view conformity assessment with the European Directives requirements, in the framework of the Notified Body for Conformity Assessment (OEC-INSEMEX). The paperwork presents aspects regarding competency testing provided in the RENAR policy for accredited or accrediting-in-progress laboratories, as requirement for proving and monitoring laboratory competency for testing/calibration in the field for which accreditation was applied for/granted.